Improvement in extension-ladders



UNITED STATES PATENT OFFICE.

ROBERT GILCHRIEST, OF LOUISVILLE, KENTUCKY.

IMPROVEMENT IN EXTENSION-LADDERS.

Specification forming part of Letters Patent No. 164,442, dated June 15,1875 application iled March 13,1875.

To all whom it may concern Beit known that I, ROBERT GILcHEIEsT, ofLouisville, in the county of Jefferson and State of Kentucky, haveinvented a new and valuable Improvement in Extension-Ladders 5 and I dohereby declare that the following is a' full, clear, and exactdescription of the construction and operation of the same, referencebeing had to the annexed drawings making a part of this specification,and to the letters and figures of reference marked thereon.

Figure 1 of the drawing is a representation of a perspective view of myladder, and Fig. 2 is a sectional view of the same. Fig. 3 is a detailView.

This invention has relation to ladders which are especially designed forthe use of firemen to enable them to attain high altitudes; and thenature of my invention consists mainly in the employment of ladders ofdifferent widths, so that their ends can be lapped one within the otherin putting the sections together, in combination with removablepivot-bolts for each section, and with means for raising and loweringthe sections conveniently, and for rigidly uniting them when erected inproper position.

In the annexed drawings, A designates the base or foundation for theextension-ladder, and B B are two standards, which are tenoned into thebase A, and sustained by means oi' hooked rods, to which swivels may beapplied, if desired. The rods c hook into eyes on the base A and tirmlyhold the standards B B. C C designate extensions for the base A, whichare flat bars of any suitable length, having tubes c on their ends toreceive other bars for elongating the auxiliary extensions. O11 theopposite ends ot' bars (l are rods c', which enter eyes d d on the baseA, and thus firmly unite the bars thereto. These bars may be applied tothe ends or sides of the base A, or to both the ends and sides thereof,and through these bars slots are made to receive supporting-legs D. Thelegs D have a number of holes through them for receiving pins e, bymeans of which the base A can be leveled on uneven ground. I also employlegs and pins for the base A itself for the same purpose as I have namedfor the legs and pins above described. The first or lowest and widestladder E is pivoted at the middle of its len gthV to a bolt, j', appliednear the upper ends of the standards B B, so that this ladder can beinclined as may be desired. Below the pivot-bolt j' are the rounds g ofthe first ladder, and at the upper end of this ladder is a pivot-bolt,f1, which passes 4through the second ladder El at the middle ot' thelength thereof, and on which this ladder can be vibrated. The rounds got' the second ladder, which are below the bolt f1, together with thisbolt, complete the number ot' rounds for the first ladder above the boltf, this latter bolt serving as one of the rounds. The upper end of thesecond ladder El has a bolt, f2, through it, which passes through thethird ladder E2 at the middle of its length, and forms a pivot for thisthird ladder. The pivot-bolt f2 and the rounds between it and bolt f1complete the number of rounds for the second ladder. In this way anydesired number of ladders may be connected together. The lower ends ofeach one of the ladders are formed so that they will bear against thepivot-bolt of thenext ladder, and when the ladders are so adjusted theywill be in the same plane, as shown in Fig. l, in which position theladders are rigidly held by means of finger-bolts h, to which jointedpieces h are applied for safely holding them in their places. To theinner sides of the uprights of all the ladders, and at the lower endsthereof, I secure eyes j, and a short distance above these eyes are eyes7c, which latter receive levers L, for the purpose of aiding the firemenin adjusting the ladders. G G are pulleys, which are attached to the bedA behind the ladder, and around which ropes or chains are passed, whichare hooked to the 'eyes j of the lower ladder, and used to raise theladder and hold it at any desired inclination. The second and thirdladders can also be adjusted by means of the ropes and pulleys. Y

Vhen the ladder E is upright its lower end bears against a horizontalbar, f3, secured to the standards B B, and it is tixed by means of thefinger-bolts h precisely as the upper ladders are tixed.

NVhat I claim as new, and desire to secure by Letters Patent, is-n 1.Two or more ladders, E El, pivoted to@ In testimony that. I claim theabove I have hereunto subscribed my name in the presence of twowitnesses.

Renner GILonnInsT.

Witnesses:

J AMES REEDY, THOMAS SHEA.

